Yarn manufacture can include twisting together of long strands of films, tapes and/or threads to form the yarns such as used in the manufacture of carpet. Breaks can occur in the yarn, however, requiring repair; the shearing can be inadvertent as when too much tension is applied at the ends or as a purposeful occurrence to form longer yarn lengths. There are numerous methods available in the art to effect repair.
In thermoplastic yarn manufacture for carpet makers using tapes or film, the task can be somewhat more complicated; the tapes undergo twisting during manufacture; heat-splicing then requires each tape end to be untwisted prior to actual application of heat. Also, there are strength and bulk limitations: (i) shear strength of the spliced tapes must not fall below a set value, say 3 lb. tensile pull for a 3700-denier yarn; and (ii) all-over diameter or maximum transverse width of the final seal must be below a minimum eyelet size of the tufting needles later used in forming carpet. Still further, the splicing wand should be portable and carry its own power supply so that mending can take place away from usual work stations.